well heres a trick i learned, and it only works if the intake isn't sealing to the head right on the top. while it is idleing, spray carb cleaner down both valleys where the intake meets the head, if you heare the idle speed pick up you know yopu have a problem. if it is a small enough leak you won't notice it on a vacuum gauge:Smarty: try this maybe.
ugh.... Looks like the only thing left is the intake seal. This weekend it is coming off and getting resealed. I had a feeling this would happen. I used a new sealer that wasn't silicone based, and I think I screwed up when I did it. Because if the surfaces aren't 100% flat, they will not seal. I replaced the rest of the replaceable parts tonight and checked dwell and timing. Not a fan of backtracking.
Adam also be sure you don't have a "chebby" carb gasket if your running a Quadrajet ! It must be a Buick type gasket to work correct . It would run lean with the "chebby " gasket ! ou: Check intake and carb gaskets !!!!!! Good Luck , and also if you bought the green LeSabe back at least you'd have a Buick parts runner !:Brow: Good Luck Adam ...........................:TU: :TU:
Update::::: I pulled the intake tonight and resealed everything. Cleaned up the valley pan gasket and RTV'ed it on both sides. ' Seems to be running much better so far. I didn't get to take if for a spin, but tomorrow, I will. It still has a bit of a blip in the idle, but I think that has been there for a while...even before the intake swap. Also, it seems to be running slightly rich still. Would changing the intake make it run rich? Stock intake to a B4B....doesn't seem right. I would guess it would run lean if anything.
FWIW I had an issue like this that turned out simply to be cheap wires that cross-fired literally because they were physically crossed. Correct firing order, but where their physical paths to their respective cylinders crossed, the spark would jump between wires and get erratic firing. Have you done the timing light check on each cylinder?
wow old thread here... Erik it turned out to be a matter of too much vac advance - and therefore pulling too much timing at idle. I made a "vac advance stop" with the help of IgnitionMan on BuickStreet and all is well again. The car actually runs better than it ever has. I also put a recurve kit in it from Crane....kicks butt now!
